jb Updated Tantalum Capacitors in Various of Types

10μF 30 VDC-rated tantalum capacitors, solid electrolyte epoxy-dipped style.
A tantalum electrolytic capacitor is an electrolytic capacitor, a passive component of electronic circuits. It consists of a pellet of porous tantalum metal as an anode, covered by an insulating oxide layer that forms the dielectric, surrounded by liquid or solid electrolyte as a cathode. Because of its very thin and relatively high permittivity dielectric layer, the tantalum capacitor distinguishes itself from other conventional and electrolytic capacitors in having high capacitance per volume (high volumetric efficiency) and lower weight.

Tantalum is a conflict mineral. Tantalum electrolytic capacitors are considerably more expensive than comparable aluminum electrolytic capacitors.

Tantalum capacitors are inherently polarized components. Reverse voltage can destroy the capacitor. Non-polar or bipolar tantalum capacitors are made by effectively connecting two polarized capacitors in series, with the anodes oriented in opposite directions.

Characteristics of the different oxide layers in tantalum and niobium electrolytic capacitors
Dielectric Relative Oxide Breakdown Dielectric layer
permittivity structure voltage thickness
(V/μm) (nm/V)
Tantalum pentoxide, Ta2O5 27 Amorphous 625 1.7
Niobium pentoxide, Nb2O5 41 Amorphous 400 2.5